text: The Oseen equations are, in case of an object moving with a steady flow velocity U through the fluid—which is at rest far from the object—and in a frame of reference attached to the object:
  where
  * u is the disturbance in flow velocity induced by the moving object, i.e. the total flow velocity in the frame of reference moving with the object is −U + u,
  * p is the pressure,
  * ρ is the density of the fluid,
  * μ is the dynamic viscosity,
  * &nabla; is the gradient operator, and
  * &nabla; is the Laplace operator.
  The boundary conditions for the Oseen flow around a rigid object are:
  with r the distance from the objects center, and p' the undisturbed pressure far from the object.